I can't believe how many people are missing the point of this feature, or decrying it as something terrible, or even conceiving a way in which it could possibly be used to ruin a game experience.
In all likelihood, this feature will only be used by choice, by those who need it. It will cost nothing, and it will allow people who are inexperienced with video games to understand how to beat them. As far as I know, features quite like this have never been implemented (together) in a video game before. But I'm wondering about what boundaries a patent like this would have, because it doesn't seem like the sort of idea you could patent. Elements of it have been around in many games, as other people have noted.
Anyway, as far as I can see it, the only valid concern one could possibly have about such a feature, is that it will make new generations of gamers less tolerant and perhaps less proficient at playing video games; and the current generation is already worse than the previous generation. I'd like to see a couple of 13 year-olds wrestle with Contra or Final Fantasy (the original) for a few hours and see where they get. This will make many people think less, but ensure that anyone who takes advantage of it can enjoy their game fully.
It's obvious that this is a step in the right direction; the only thing unclear is how big this step will be, and how long Nintendo will walk on the path for.